150 



Our Food Mollusks 



center of the disk. Radiating from this on the under 

 side of each arm, and extending to its tip, are grooves 

 from which project a great number of fleshy tubes, each 

 provided with a disk-like sucker at its end. These are 

 the tube feet, and are used in locomotion. 



One would hardly imagine, after examining a dried 

 specimen, with its hard, unyielding body, that it might 



FIG. 38. Common Starfish of the North Atlantic Coast. 



be capable of much bending in any part. But the living 

 animal is able to bend these arms upward, downward and 

 sideways, to an extreme degree, by the contraction of 

 muscles connecting the plates of the skeleton. 



The animal creeps on the bottom with great delibera- 

 tion. Six inches in a minute is fair speed for a large 



